1. Field of the Invention
This invention relates to a system for conveying a plurality of .alpha.-shaped torsion springs and separating the torsion springs one by one.
2. Description of the Prior Art
As shown in FIG. 8, an .alpha.-shaped torsion spring comprises a coiled portion 2 and a pair of leg portions 3a and 3b. Such .alpha.-shaped torsion springs 1 are used in various products. Various systems have been developed in order to convey a plurality of .alpha.-shaped torsion springs to a predetermined position and separate them one by one when incorporating the .alpha.-shaped torsion spring into a work.
In a common torsion spring conveying and separating system shown in FIGS. 9 and 10, the .alpha.-shaped torsion springs 1 are first arranged by means of a vibrating bowl feeder (not shown) in a row with the coiled portion 2 of each .alpha.-shaped torsion spring 1 extending vertical and the leg portions 3a and 3b projecting in the respective predetermined directions, and then are conveyed to a chucking position by means of a linear vibrating feeder 4. The linear vibrating feeder 4 comprises a conveyor rail 5 which is substantially U-shaped in cross-section. A narrow groove 6 is formed in the bottom of the rail 5 and each .alpha.-shaped torsion spring 1 is conveyed along the rail 5 in the direction of arrow A while the position of the spring 1 is regulated by the leg portion 3b fitted in the groove 6. The .alpha.-shaped torsion spring 1 is stopped when it abuts against a stopper 7 formed on the front end of the rail 5. A chucking device comprising a center pin 8a and a chucking claw 8b is disposed above the coiled portion 2 of the leading .alpha.-shaped torsion spring 1. The center pin 8a and the chucking claw 8b are moved downward so that the center pin 8a enters the hole 2a of the coiled portion 2, and then the chucking claw 8b is moved toward the coiled portion 2 through a passage 9 formed in a side wall 5a of the rail 5, whereby the leading spring 1 is caught between the center pin 8a and the chucking claw 8b. Then when the chucking device is moved upward, the leading spring 1 is separated from the other springs.
However since the leg portions 3a and 3b keep curl of the wire of which the .alpha.-shaped torsion spring 1 has been formed, the leg portion 3b is apt to project out of the groove 6 during conveyance by the linear vibrating feeder 4 to catch another spring or to get out of the groove 6 to move the spring 1 out of the predetermined position, whereby the feeder 4 can get jammed.
When a winding machine is incorporated with a system for incorporating the spring into a work and the spring formed by the winding machine is directly incorporated into the work as disclosed, for instance, in U.S. Pat. No. 4,524,596, the system for conveying the spring can be eliminated. But this approach is disadvantageous in that when the winding machine having a complicated mechanism is incorporated with the system for incorporating the spring into a work, maintenance cost is substantially increased and maintenance of the system takes an expert operator.